Road finishing machine



SePt- 18, 1962 H. A. BARBER ETAL 3,054,334

ROAD FINISHING MACHINE 7 Sheets-Sheet l Filed Sept. 4, 1959 DH .Uhm

INVENTORS HARRY A EJArzEL Armee @Awal d .Urn

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sePt- 18 1962 H. A. BARBER ETAL ROAD FINISHING MACHINE Filed Sept. 4, 1959 NVENTORS HARRY A. EDAREEK .JAMES FL AUEl. f j /M-romeya Sept. 18, 1962 H. BARBER ETAL ROAD FINISHING MACHINE 7 Sheets-Sheet 3 Filed Sept. 4, 1959 INVENTORS FIG. 4 HARRY A. rArzeEsL JAME E AUEl @Q76 WA :'Ar-rorzmaye H. A. BARBER ETAL 3,054,334

ROAD FINISHING MACHINE 'T Sheets-Sheet 4 Sept. 18, 1962 Filed sept. 4, 1959 I.: ioszo. al w I w .Pino 55E .l 7 5 M NAA 4 4, l e m56 IIIL l/r E N ,N1 r @H in 5 4 IAF 5 5/ 5 QM WJ AHA 5 J 4 5 x m J-U E lo 4 .a 5 5 Q 5 5 L .n.T/ \|,wl|||||| m. o 5

EDY fz/neq-Tcnmy '7 Sheets-Sheet 5 H. A. BARBER ETAL Sept. 18, 1962 ROAD FINISHING MACHINE Filed Sept. 4. 1959 mNT mi A NVENTORS H AZIZY A. BARBER. .JAA/1&6 F. @ADEL lfATTozNeye Sept 18 1962 H. A. BARBER ETAL 3,054,334

ROAD FINISHING MACHINE 7 Sheets-Sheet 6 Filed Sept. 4. 1959 INVENToRs HAlztZYA. BARBER. JAMEs F. SAUEL sept. 1s, 1962 Filed Sept. 4, 195

H. A. BARBER ETAL ROAD FINISHING MACHINE '7 Sheets-Sheet '7 v A J/ INVENTORS HARRY A BARBEK .JAmae F- AuEr-L E, M z/gfA-TTOIZNEYS 3,054,334 ROAD FINISHING MACHINE Harry A. Barber and James F. Sauer, Aurora, lll., assignors to Barber-Greene Company, Aurora, Ill., a corporation of Illinois Filed sept. 4, 1959, ser. No. 838,284 Claims. (Cl. 94--46) This invention relates to improvements in road finishing machines of the type which lay and finish bituminous or like paving materials along a roadway.

A principal object of the invention is to improve upon the road finishing machines heretofore in use by providing increased storage capacity and an improved suspension system for the machine stabilizing the machine and taking overloads from the traction devices upon increases in loads on the storage hopper for the machine.

A further object of the invention is to provide an improved form of road finishing machine supported and propelled by traction devices having an auxiliary ground engaging load bearing unit of low overall height mounted beneath the storage hopper for bituminous or a like paving material, supporting the hopper upon an overload on the main traction devices.

Another object of the invention is to provide a road finishing machine and suspension system therefor, giving the machine improved balancing characteristics at high and low speeds.

A still further object of the invention is to provide an improved balancing stabilizer for road finishing machines and the like coming into operation to balance the load upon the tendency of the machine to pivot in either direction about an axis extending transversely of the machine.

A still further object of the invention is to provide a simplied and improved suspension for road finishing machines and the like, in which the machine may be supported and propelled on traction wheels or on continuous traction tread devices, as selected.

Still another object of the invention is to provide a simplified form of road finishing machine having improved paving material storage and delivery facilities.

A further object of the invention is to improve upon road finishing machines of the type used to lay and finish bituminous paving materials by extending the hopper for the paving materials for the length of the machine and by providing an auxiliary load bearing unit at the front of the hopper, normally out of supporting engagement with the hopper, and supporting the hopper as the main traction devices tend to become overloaded.

A still further object of the invention is to provide a load finishing machine of the class described, in which the storage hopper is transversely pivoted to the main frame of the machine adjacent the rear end thereof and extends for the length of the main frame of the machine and beyond the forward end thereof, and carries an auxiliary load bearing unit in the form of individual tread devices mounted on a common axle, pivoted intermediate its ends for movement about an axis extending longitudinally of thel machine, and in which the suspension for the main frame of the machine normally holds the hopper out of engagement with the tread devices and accommodates the hopper to be supported by the tread devices as the hopper is loaded with asphalt to the extent that it would tend to overload the main traction devices.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

FIGURE 1 is a view in side elevation of a road nishing machine constructed in accordance with the invention;

FIGURE 2 is a fragmentary plan view of the road finishing machine shown in FIGURE l, With certain parts thereof broken away;

FIGURE 3 is a fragmentary perspective view of the machine looking at the machine fro-m. the front end portion thereof and showing the storage hopper for the asphalt in a fully extended position;

FIGURE 4 is a front end View of the machine showing the storage hopper for the asphalt in a fully retracted position;

FIGURE 5 is a fragmentary plan view of the rear end portion of the machine with certain parts broken away and certain other parts shown in horizontal section, and illustrating the vertically guided gates controlling the discharge of asphalt from the storage hopper;

FIGURE 6 is a fragmentary rear end view of the control gates shown in FIGURE 5 FIGURE 7 is a fragmentary sectional view taken substantially along lines VII-VII of FIGURE 6;

FIGURE 8 is a fragmentary sectional view taken substantially along lines VIIL-VIII of FIGURE 6;

FIGURE 9 is a diagrammatic View illustrating the stabilizing suspension for the finishing machine;

FIGURE l0 is an enlarged fragmentary side view illustrating the suspension when supporting the machine on rubber tire mounted wheels;

FIGURE l1 is an enlarged fragmentary plan view of the suspension means shown in FIGURE 10; l

FIGURE 12 is a view somewhat similar to FIGURE 11, but showing one of the spring casings broken away and partially shown in section;

FIGURE 13 is a partial fragmentary horizontal sectional view taken through the gear housing and support for the traction devices; and

FIGURE 14 is a fragmentary view in side elevation with certain parts broken away and certain other parts shown in section and illustrating the suspension support for the machine on continuous traction tread devices.

In the embodiment of the invention illustrated in the drawings, the machine as shown in FIGURE l generally` comprises a traction unit 10 including a main frame 11 mounted on traction devices, such as rubber tired wheels 12 and having a hopper 13 for hot asphalt extending for the length of the main frame 11, and pivotally connected to said main frame adjacent its rear end for limited vertical movement with respect to the main frame about coaxial pivot shafts 15.

The forward end portion of the hopper 13 is supported when loaded with asphalt on an auxiliary load bearing unit including a pair of laterally spaced tread devices 16 mounted on opposite ends of a transverse axle 17 pivotally and slidably mounted beneath the bottom of the forward end portion of the hopper 13 on a longitudinally extending pivot shaft 18 carried in slotted guides 14 depending from the hopper 13 (FIGURES 4 and 9).

The machine also includes a screed or tamper and strike-olf unit 19 spaced rearwardly of the rear end portion of the main frame 11 and the discharge end portion of the hopper 13, and suspended'from laterally spaced leveling arms 20 extending forwardly along the main frame 11 along the outsides of the wheels 12 and pivotally connected at their forward ends to lugs 21 on pivot pins 22. The lugs 21 extend from auxiliary front arms 23, transversely pivoted to opposite sides of the main frame 11 on pivot pins 24, and extending forwardly of the pivot pins 24 along the outsides of the wheels 12, and secured at their forward ends to tread frames 2S for the tread devices 16 of the auxiliary load bearing unit.

The tamper and strike-off unit may be of a lform like that shown and described in Patent No. 2,351,593 which issued to Harry A. Barber on June 20, 1944, so need not herein be shown or described in detail, except to point Patented Sept. 18, 1962` out that the leveling arms 20, pivotally connected at their forward ends to the auxiliary front arms 23 intermediate the ends of said auxiliary arms, will move relatively to the main frame 11 in a vertical direction about the axes of the pivot pins 22 and 24 as the wheels 12 and tread devices 16 encounter grade changes in the pavement. Angular movement of the tamper and strike-olf unit about axes extending transversely of the machine to conform to changes in grade, will thus be averaged out and the tamper and strike-off unit 19 will automatically compensate for variations in grade in advance of the tamper and strike-off unit 19, as in Patent No. 2,138,828 dated December 6, 1938.

In the present form of the invention, the leveling arms 20 are pivotally connected at their forward ends intermediate the ends of the auxiliary front arms 23. The front arms 23, in turn are pivoted to the transverse center of the machine at one end and are mounted at their forward ends on the tread devices 16 and move vertically therewith. It should be understood from the foregoing that during the paving operation the tamper and strikeoff unit 19 rides directly on and nishes the pavement, while the auxiliary load bearing unit 16 rides along the unfinished roadway and senses variations in the pavement. The linkage arrangement just described thus reduces the amount of angular movement transmitted by the driving wheels 12 and the front tread devices 16, which tread devices serve as leveling shoes as in Patent No. 2,138,828. The front tread devices 16 and leveling arms 20, thus average out irregularities in the pavement and improve the automatic leveling action over former road finishing machines operating on similar principles due to the reduction in movement transmitted by either the front tread devices or the driving wheels, when operating over an undulating or irregular sub-grade.

The leveling arms 20 have connecting lugs 26 extending generally upwardly therefrom intermediate the ends thereof, and forming connectors for pivot pins 27, pivotally connecting the piston rods 29 of hydraulic jacks 30, to said lugs and arms. The hydraulic jacks 30 extend within side frame members 31 of the main frame 11 and are suitably pivotally connected thereto at their upper ends. The hydraulic jacks 30 thus serve to elevate the leveling arms 20 and the tamper and strike-off unit 19 above the ground, when it is desired to transport the machine from place to place, it being understood that during the paving operation, pressure is released from the hydraulic jacks 30 to accommodate the tamper and strike-off unit to have leveling engagement with the ground.

Hydraulic jacks 33 are pivotally connected to the side frame members 31 on lugs 34 and depend therefrom. Extensible piston rods 35 of the hydraulic jacks 33 are pivotally connected at their lower ends to lugs 36 extending upwardly from the auxiliary arms 23, intermediate the ends thereof. The hydraulic jacks 33 serve to elevate the auxiliary arms 23, tread devices 16 and hopper 13, when it is desired to propel the machine from place to place. During the road finishing operation, fluid pressure is relieved from the hydraulic jacks 33, to accommodate downward movement of the tread devices 16 into engagement with the ground. Downward movement of the hopper 13 is limited by chains 40 connected at their upper ends to connectors 38 extending inwardly of the side frame members 11, and connected at their lower ends to connectors 39 on opposite outer sides of the pivoted hopper 13.

The hopper 13, pivoted to the main frame 11 at its rear or discharge end and limited in downward movement with respect to the main frame 11 by the chains 40, includes parallel spaced side frame members 41, suitably connected together along the length thereof, and an intermediate divider 43 extending along the center of the hopper 13 and dividing said hopper into two compartments on each side of said divider, along which move endless chain and ight conveyors 44, for progressing the hot asphalt for discharge at the rear or discharging end portion of said hopper under the control of two vertically guided outer gates 45, and a vertically guided center gate 46 extending along each side of the divider 43.

The side frame members 41 are pivotally supported at the rear ends thereof on the pivot pins 15, extending outwardly of plates 47, secured to a transverse bar 49 mounted at its ends on arms 50, forming rear extensions of the side frame members 31 of the main frame 11. The plates 47 are welded or otherwise secured to the cross bar 49 and extend forwardly and downwardly therefrom in parallel relation with respect to each other, and have vertically extending guides l51 extending along their inner end portions. The guides 51 are herein shown as being in the form of angles welded or otherwise secured to the plates 47 along the ends of their legs, and being slidably engaged by angle guides 53 welded or otherwise secured to the outer edges of the gates 45. The vertical guides 53 extend along opposite edges of the gates 45. The inner guides 53 have guiding engagement with rods or posts 55, secured at their upper ends to plates 56 suitably secured to and extending forwardly of the cross bar 49. The posts 55 are welded or otherwise secured to the plates 56 and depend therefrom and may be suitably braced to said plates 56 and cross bar 49. The depending posts 55 also form guide members for guides 57 extending laterally from opposite edges of the center gate 46.

The outer gates 45 are vertically adjusted by operation of individual hand cranks 58 through suitable linkage connections, which are no part of the present invention so need not herein be described in detail.

The center gate 46 is vertically adjusted by a hand crank 70 rotatably mounted on a bracket 71, suitably mounted on the cross bar 49. The hand crank 70 rotatably drives an inwardly and forwardly spaced threaded rod 73, through a chain and sprocket drive indicated by reference character 74. The threaded rod 73 is threaded within a hollow shaft or rod 75 extending between connecting ears 76 extending rearwardly of the gate 46, and pivotally connected to said ears as by a pivot pin 77. Rotation of the hand crank 70 will thus raise and lower the gate 46 and retain said gate in a selected position of adjustment in an obvious manner.

It may be seen from the foregoing that the three gates 4S, 45 and 46 at the rear or discharge end of the hopper 13 may be individually adjusted to control the supply of asphalt to a spreader screw 79 between the discharge end of the hopper 13 and the tamper and strike-off unit 19, and that said gates may readily be adjusted from the tamper and strike-off unit 19 by the operator of the tamper and strike-off unit without stopping the machine.

The forward or receiving end portion of the hopper 13 includes side wings 80 suitably hinged to the hopper along the outer sides of the conveyors 44. The side wings 80 are raised about their pivotal axes from the position shown in FIGURE 3 to the position shown in FIGURE 4, to feed the hot asphalt on said side wings into the conveyor 44, by hydraulic jacks 81, operatively connected with toggle links 83, for raising the side wings of the hopper to automatically feed the material from the side wings into the conveyors 44. The toggle links and hydraulic jacks and their operative connections to the side wings 80 form no part of the present invention so need not herein be shown, or described further.

An elevated operators platform is provided at the rear of the machine, rearwardly of the side wings 80. The operators platform `85 has spaced operators seats 86 thereon (FIGURE 4), with the usual controls accessible from said seats and also forms a part of the frame structure of the main frame, and bridges the hopper 13 and the conveyors 44, accommodating said conveyors to pass along a tunnel 87 beneath said operators platform to thc control gates 45 and 46. The tunnel 87 thus provides a storage space for the hot asphalt, increasing the live storage of asphalt over former finishing machines, accommodating the asphalt to be stored for the entire length of the machine and making it unnecessary to build up a high pile of hot asphalt at the receiving end of the hopper 13.

At the front end of the machine and extending trans- -versely thereacross is a push -bar 88 pivotally mounted at the front end of the hopper for movement about the axis of a vertically extending pivot pin 89. The push 'bar 88 has push rollers 901 journalled at opposite ends thereof for rotation about horizontal axes. The push rollers 90 engage the rear tires of a truck (not shown) discharging asphalt into the hopper 13, and are free to swivel about the axis of the pivot pin 89 and therefore center the load on the machine at the pivot pin 89 and make it unnecessary to line the truck up squarely with the front end of the machine.

Referring now to FIGURES 2 and 9 to 13 inclusive and the suspension system for the machine, the chassis or main frame of the machine is mounted for pivotal movement about tandem drive shafts 93 under the control of preloaded stabilizer springs 94 in spring casings 95, which maintain the wheels 12 in engagement with the ground regardless of irregularities in the ground. As the frame 11 is loaded by loading of the hopper 13 with hot asphalt, the main frame 11 will pivot about the tandem drive shafts 93 and accommodate the tread devices 16 in engagement with the ground to support said hopper and to thereby provide a six point suspension for the machine, as will now be described.

The Wheels 12, as shown in FIGURE 13 are mounted on'axles 96 rotatably journalled in an inner end Wall 98 of a gear housing or casing 97 for reduction gearing indicated generally by reference character 99. The reduction gearing 99 drives the two axles 96 and wheels 12 thereon at the same rates of speed from the tandem drive shaft 93. The axles 96 project outwardly of the gear housing 97 and are encircled by annular supports 192 extending outwardly of the outer Wall of the gear housing 97 and forming bearing supports for said shafts. Each tandem drive shaft 93 is suitably journalled in opposite side walls of the gear housing 97, and has a drive sprocket 100 keyed or otherwise secured to the outer end portion thereof and driven from a drive shaft 101 through a chain and sprocket drive 103 (FIGURE 10). The drive shafts 101 are independently driven through a suitable motor and transmission (not shown), to effect steering of the machine by driving the wheels on one side of the machine at a different rate of speed than the wheels on the opposite side of the machine, as shown and described in a companion application Serial No. 847,533, Iled by Guy Banister on October 20,1959, now Patent No. 2,996,- 933 and entitled, Power Steering System for Skid Steered Vehicles, and no part of the present invention so not herein shown or described further.

The gear housing 97 has a generally cylindrical casing portion 104 enclosing the drive sprocket ofthe chain and sprocket drive 103, open at its upper end portion to accommodate the chain of the chain and sprocket drive 103 to pass about and mesh with the sprocket 100. The casing 104 has an end plate 105 welded or otherwise secured tothe outer end thereof, having a pivot shaft 106 secured thereto and extending outwardly therefrom. The pivot shaft 106 is rotatably journalled coaxial with the pivot shaft 24, in a bearing block 107 mounted on a central depending portion 199 of a side frame member 31 'of the main frame 11. The pivot shafts 166 being coaxial with the tandem drive shafts 93, thus mount the main frame 11 on the housings 97 and traction wheels 12 for rocking movement about said tandem drive shafts.

VThe loadV stabilizer springs 94 in the casings 95 form load stabilizers, stabilizing the main frame'll on the wheels 12, Vand picking up and stabilizing the unbalanced load when said main frame has a tendency to pivot in either direction. One casing 95 and spring 94 face in one 6. direction and have stabilizing connection with one end of the housing 97 and the other casing 95 and spring 94 face in an opposite direction and have stabilizing connection with the opposite end of the same housing 97.

As shown in FIGURE 12, the spring 94 encircles a rod extending through an end of the casing 95 and having connection with an upright lever arm 111 of a bell crank 112. The rod 110 extends along a tube 115 in casing 95, and is retained to said tube by lock nuts 108. The tube 115- has a stop member 113 secured to its inner end and forming a seat for the spring 94. The spring 94 is preloaded by a nut 116 threaded on the tube 115 and abutting a rod end closure 117 for the cylinder 95, and having the rod 110y slidably movable therealong. Turning of the nut 116 will thus take up or release tension of the spring 94 and vary the load on said spring. The cylinder 95 is trunnioned on the frame 11 on trunnion pins 119 mounted on trunnion supports 120, secured to and extending upwardly from a cross tube 121, forming a reenforcing cross frame member for the main frame 11. The lever arm 111 of the bellcrank 112 extendsupwardly from a tube 122 pivotally mounted on a transverse shaft 123 suitably supported at its ends in the main frame 11. The tube 122 has a lever arm 124 of the bellcrank 112 extending generally horizontally therefrom and having a link 125 pivoted to the free end thereof on a pivot pin 126 (FIGURES 2 and l1). The link 125 in turn is pivoted to an ear 127, extending upwardly from the housing 97 adjacent one end thereof, on a pivot pin 129.

The oppositely facing casing 95 is trunnioned at its head end on trunnion pins journalled in trunnion supports 131, extending upwardly from a hollow cross bar 133, reenrforcing the main frame 11 and connected between the outer frame member 31 thereof and an inner frame member 135. The casing 95 has a rod 110 extending therefrom'and pivoted to an upright arm 136I of a bellcrank 137, like the bellcrank 112. The upright arm 136 extends upwardly from a sleeve 139 journa'lled on a transverse shaft 149 mounted between the plate 135 and the auxiliary frame member 59 of the main frame 11. The sleeve 139 has ahorizontally extending,l arm 141 extending therefrom (FIGURE 1l), having a link 143 depending therefrom and pivotally connected at its lower end to an ear extending upwardly from the opposite end of the housing 97 from the ear 127. A

When the hopper 13 is partially full of asphalt, the tread devices 16 will be in engagement with the ground but will not support the hopper 13, and the machine'will beV supported on the wheels 12, which may independently pivot about the center of the tandem drive shafts 93 maintaining an equal load distribution and imparting very little movement to the main frame. Movement of thev mainframe is, therefore, stabilized by the balance-stabilizers inthe form ofthe two encased preloaded compression springs 94 exerting their forces in oppositedirectionls and inactive, except When the main frame 11 has a tendency to pivot in either direction at which time the springs 94 will pick up and stabilize the unbalanced load. Y When the machine is laying a road with pavement, the tamper and finisher 19 will be supported bythe mat 0f paving material. This will relieve weight from the rear end of the machine and the weight of the asphalt in the hopper 13 -will tend to pivot said hopper and. thev main frame 1,1 about the axis of the tandem drive shafts 93 to be supported on the tread devices 16. The tread devices 16 on the axle 1'7, may then pivot about the of the shaft 18, While the hopper 13 may pivot about the axes of the coaxial pivot shafts 15, as irregularities are encountered. I i Y Thus, the wheels 12 and tread devices 16 will be mairitained in engagement with the road regardless of irregularities in the road. Said wheels, together with the tread devices forming an auxiliary load bearing unit will in effect form a six point suspension having articulated motion at all points so that the wheels and tread devices during the paving operation will remain in contact with a rough or undulating pavement.

The auxiliary load bearing unit in the form of the continuous tread devices 16, supported on the longitudinally pivoted axle 17, in effect comes into operation on overloading of the hopper 13 and thereby relieves the traction wheels 12 from overload conditions and cooperates with the transverse pivotal support for the traction wheels to maintain all of the traction wheels in engagement with the ground by operation of the load stabilizing springs 94.

In FIGURE 14, we have diagrammatically shown an adaptation of the suspension system to continuous traction tread devices 166. In this form of the invention an individual tread frame 167 is provided for each side of the machine and pivotally supports the main frame 11 for pivotal movement about the axis of a drive shaft 169 in a manner similar to which the housings 97 pivotally support the main frame 11 on the wheels 12. The tread frame 167 has a drive sprocket 170 on a drive shaft 175 suitably journalled at one end thereof. The sprocket 170 is driven from the shaft 169 through a chain and sprocket drive 171. The shaft 169 is driven from the transmission shaft 101 through a chain and sprocket drive 173 in a manner similar to which the shaft 93 is driven from said transmission shaft. A tread drive sprocket 174 on the drive shaft 175 is driven from the sprocket 170, and meshes with and drives a continuous traction tread device 166. An idler sprocket 146 is rotatably mounted on a transverse shaft 147, mounted at the opposite end of the tread frame 167 from the drive sprocket 174, and serves as a direction changing device for the continuous tread device 166. Support rollers 149 extend across the tread frame 167 and are suitably journalled thereon to support the lower run of the continuous traction tread device 166 during operation of the machine.

The balance stabilizing means includes the two oppositely acting preloaded stabilizing springs 94, carried in the casings 95, trunnioned within the main frame 11 as in FIGURES 2, 11 and 12. One rod 110 is pivotally connected with an upright arm 150, extending upwardly from a tube or pipe 151 pivotally mounted on the transverse shaft 123. A lever arm 153 depends from the tube 151 and has a connecting link 154 pivotally connected thereto, and connecting the lever arm 153 with a depending lever arm 155, depending from a tube 156, pivotally mounted on the shaft 140. A lever arm 160 extends horizontally from the tube 156 and is pivotally connected at its outer end to a link 161, depending therefrom and pivotally connected at its lower end to an ear 163, extending upwardly from the tread frame 167 adjacent the outer end thereof. The stabilizing spring 94 connected with the lever arm 150 through the rod 110, thus stabilizes movement of the tread frame 167 about the axis of the shaft 169 in one direction.

Movement of the tread frame 167 in the opposite direction is stabilized by the opposite stabilizing spring 94 and rod 110 pivotally connected to the upper end of a lever arm 165 extending upwardly from the tube 156.

The balance stabilizing springs 94 on each side of the vehicle therefore accommodate the continuous traction devices 166 on each side of the vehicle to pivot independently of each other about the center of the tandem drive shafts 169 and balance the main frame 11 during traveling from place to place, when the tamper and leveling unit 19 is raised off the ground and the tread devices 16 are also out of engagement with the ground and the hopper 15 is empty, and during the operation of paving when the tamper and leveling unit and tread devices 16 are in engagement with the ground. The continuous traction devices 166 and tread devices 16 thus provide a six point suspension for the vehicle in which the motion of the vehicle is articulated at all points of the suspension in the same manner as when the vehicle is supported on the rubber tired wheels 12.

The machine may thus be converted from a wheel supported machine to a continuous traction tread device supported machine by interchanging the tread frames 167 for the housings 97 and the bellcrank arrangements of the stabilizing linkage connections.

It may be seen from the foregoing that an improved form of road tinishing machine has been provided in which the storage hopper and asphalt feeder of the machine extends for the entire length of the machine through a. tunnel beneath the operators platform and is pivoted at the rear end of the machine, and is supported at its front end, when loaded with asphalt, on a load bearing unit of low overall height, thereby reducing the overall height of the hopper, increasing the capacity of the machine and retaining the balance point of the machine centered with respect to the main frame thereof.

It may further be seen that the pivoting of the chassis or main frame of the machine on the supports for the traction devices intermediate the ends of the supports, coaxial with the tandem drive shafts for the traction devices, together with the stabilizing balancing springs restraining rocking movement of the chassis about the axis of the tandem drive shafts, and the load bearing unit supporting the hopper 13 upon loading of the hopper with asphalt, provides articulated motion for the traction devices and auxiliary load bearing unit, maintaining all points in engagement with the load regardless of irregularities in the road, and supporting the chassis for travel along the road at high and low speeds in a balanced condition.

While we have herein shown and described several forms in which our invention may be embodied, it should be understood that various variations in the invention may be attained without departing from the spirit and scope of the novel concepts thereof, as defined by the claims appended hereto.

We claim as our invention:

1. In a road paving machine, a frame, traction devices supporting and propelling said frame, a strike off unit spaced rearwardly of said frame, a hopper transversely pivoted to said frame adjacent the rear end thereof, and extending for substantially the length of said frame, an auxiliary load bearing unit mounted beneath the forward end portion of said hopper for pivotal movement about an axis extending longitudinally of the machine, and connecting means for said strike-off unit controlling said strike-off unit to average out irregularities in the pavement comprising a pair of front arms pivotally connected to said frame adjacent the transverse center thereof and having connection with said load 4bearing unit at their forward ends, and leveling arms pivotally connected to said front arms intermediate the ends thereof, said leveling arms extending rearwardly of said frame and forming draw bars for said strike-off unit.

2. In a road paving machine, a frame, laterally spaced traction devices supporting and propelling said frame, support frames for said traction devices pivoted to said frame about a common transverse axis intermediate the ends of said frame, yieldable stabilizing means connected between said frame and said support frames for said traction devices for restraining movement of said frame about the axis of pivotal connection of said frame to said support frames for said traction devices, a strike-olf unit spaced rearwardly of said frame and connected thereto, a hopper extending substantially the length of said frame having a rear discharge end portion and having conveying means extending therealong, means pivotally mounting said hopper on said frame adjacent the rear end thereof, a load bearing unit pivotally mounted beneath said hopper at the forward end portion thereof for movement with respect thereto about an axis extending longitudinally of said frame, and means connecting said strike-off unit to said frame to level off irregularities in the pavement sensed by said load bearing unit comprising a plurality of front arms pivotally connected to said frame for movement about axes coaxial with the axes of rocking movement of said frame with respect to said traction devices and having connection with said load bearing unit at their forward ends, and leveling arms transversely pivoted to said front arms intermediate the ends thereof and extending rearwardly of said frame over said `strike-off Unit and having controlling connection therewith.

3. In a road paver, a frame, individual laterally spaced traction devices at opposite sides of said frame and support frames for said traction devices, means mounting said frame on said support frames intermediate the ends thereof for movement about a common transverse axis intermediate the ends of said frame, and stabilizing means connected between said lframe and said support frames and yieldably restraining rocking movement of said frame with respect to said support frames and maintaining said traction devices in engagement with the ground regardless of irregularities therein.

4. In a road paver, a frame, laterally spaced traction devices extending along each side of said frame, support frames for said traction devices, means for driving said traction devices including coaxial drive shafts intermediate the ends of said frame, means for supporting said frame on said support frames for movement about said drive shafts, stabilizing means yieldably restraining movement of said lframe about said drive shafts, and means loading said stabilizing means in accordance with a desired load on said traction devices.

5. In a road paver, a yframe, individual laterally spaced traction devices extending along each side of said frame, support means `for said traction devices including support frames transversely pivoted to said frame intermediate the ends of said support frames, drive means for said traction devices including drive shafts coaxial with the pivotal axes of said support fram-es, and stabilizing means connected between said frame and said support frames for yieldably restraining rocking movement of said frame about the `axis of connection of said frame to said support frames.

`6. In a vehicle, a frame, laterally spaced traction de vices extending along each side of said frame, support means for said traction devices including support frames transversely pivoted to said frame intermediate the ends of said support frames, drive means for said traction devices including drive shafts coaxial with the pivotal axes of said support frames, stabilizing means yieldably restraining movement of said frame about the axis of connection thereof to said support frames, and means loading said stabilizing means in accordance with a desired load on said traction devices.

7. A vehicle suspension comprising a frame, laterally spaced traction devices extending along opposite sides of said frame, support means for -said traction devices including support frames transversely pivoted to said frame intermediate the ends of said support frames, drive means for said traction devices including drive shafts coaxial with the pivotal axes of said support frames, stabilizing means yieldably restraining movement of Said frame about the axis of pivotal connection of said frame to said support frames, including oppositely acting load stabilizing units mounted on said frame and having operative connection with said support frames, restraining pivotal movement of said frame Iwith respect to said support frames in opposite directions, and means loading said stabilizing units in accordance with a desired load on said traction devices.

8. In a road paver, a frame, a hopper extending along said frame from the forward to rear end thereof, means pivotally mounting said hopper on said frame for movement about a transverse pivotal axis adjacent the rear end of said frame, a ground engaging load bearing unit mounted beneath the forward end portion of said hopper for supporting said hopper on the ground when loaded, laterally spaced traction devices and support means therefore mounting said frame on said traction devices for pivotal movement about a common axis intermediate the ends of support means, means normally holding said hopper out of supported engagement with said load bearing unit, and stabilizing means yieldably restraining pivotal movement of said frame about the axis of connection of said frame to said support means, and accommodating said hopper to move downwardly into supported engagement with said load bearing unit as said frame pivotally moves against said stabilizing means by the load of paving material in said hopper.

9. In a road paver, a frame, individual laterally spaced traction devices extending along each side of said frame, support means for said traction devices including support frames transversely pivoted to said frame intermediate the ends of said support means, drive means for said traction devices coaxial with the axis of pivotal connection of said frame thereto, stabilizing means yieldably restraining movement of said frame about its axis of connection to said traction devices, a hopper extending along said frame and having a receiving end at the forward end of said frame and a discharge end at the rear end of said frame, conveying means extending along said hopper from the receiving to the discharge end thereof, means pivotally connecting said hopper to said frame for movement with respect thereto about a transverse axis adjacent the rear end of said frame, a ground engaging load bearing unit carried beneath said hopper adjacent the forward end thereof and pivotally connected thereto for movement about an axis extending longitudinally thereof, means connected between said frame and said hopper, holding said hopper olf of said load bearing unit when said hopper is not fully loaded, and accommodating said hopper to move downwardly with said frame to come into engagement with said load bearing unit, to be supported thereby by pivotal movement of said frame toward said hopper effected by loading of said hopper and yielding of said stabilizing means.

10. In a road paver, a frame, traction devices supporting said frame, a hopper transversely pivoted to said frame adjacent the rear end thereof, an auxiliary loading bearing unit spaced forwardly of said traction devices in alignment therewith and mounted beneath said hopper, a vertically slidable and pivotal connection between said hopper and said load bearing unit, supportmeans for said frame on said traction devices including individual support frames extending along each side of said frame and pivotally connected thereto for movement about axes extending transversely thereof, variable length linkage connections connected between said frame and said support frames, and means yieldably restraining lengthening of said linkage connections and restraining pivotal movement of said frame about the axis of pivotal connection of said support members thereto, and accommodating the weight of material loaded onto said hopper to bring said hopper into engagement with said load bearing unit to be supported thereby.

11. In a road paver, a frame, traction devices supporting said frame, a hopper transversely pivoted to said frame adjacent the rear end thereof, an auxiliary load bearing unit spaced forwardly of said traction devices in alignment therewith and mounted beneath said hopper, a vertically slidable and pivotal connection between said hopper and said load bearing unit, support means for said traction devices including individual support members extending along each side of said frame and having said frame pivotally mounted thereon for movement about axes extending transversely thereof, variable length linkage connections connected between said frame and each of said support members including stabilizing spring means yieldably restraining lengthening of said linkage connections and pivotal movement of said frame about said support members and accommodating said hopper to come into engagement with said load bearing unit, to be supported thereby upon loading of said hopper.

12. In a road paver, a frame, traction devices supporting said frame, an auxiliary load bearing unit spaced from said traction devices at one end thereof, connecting means for said loading bearing unit, pivotally connected to said frame at the opposite end thereof from said load bearing unit, Aa hopper transversely pivoted to said frame adjacent the rear end thereof, a longitudinal pivotally and vertically slidable connection between said hopper and said load bearing unit, accommodating pivotal movement of said load bearing unit about an axis extending along the center of said frame, support members pivotally mounting said frame on said traction devices for movement about axes extending transversely of said frame, intermediate the ends of said support members, and oppositely acting stabilizing springs associated with each of said support members and connected between said frame and said support members, `and loaded to normally restrain said frame from pivotal movement about said support members, and extensible upon increases in load at one end of said frame, to accommodate said hopper to be supported by said load bearing unit upon loading of said hopper to overload said traction devices.

13. In a road paver, a frame, traction means supporting said frame, a strike-off unit spaced rearwardly of said frame, a hopper transversely pivoted to said frame adjacent the rear end thereof and having a receiving end at the forward end of said frame, conveying means for progressing material from the forward to the rear end of said hopper, a load bearing unit beneath the forward `end portion of said hopper, means pivotally and slidably connecting said load bearing unit to said hopper for pivotal movement about an axis extending longitudinally thereof, means normally retainingsaid hopper out of engagement with said load=bearingunit, leveling arms pivotally connected between the forward end portion of said frame and said strike-off unit for automatically controlling movement of said strike-off unit to level out irregularities in the pavement, means for elevating said leveling arms and strike-oit unit out of engagement with the ground for tramming, said traction means including traction devices extending along opposite sides of the machine and support members for said traction devices extending along each side of said frame, means pivotally mounting said frame on said support members for movement about a transverse axis disposed intermediate the ends of said support members, a pair of oppositely acting preloaded stabilizing springs extending along each side of said frame, said springs serving to restrain pivotal movement of said frame about said support members in opposite directions and being connected between said frame and said support members, and accommodating the loading of said hopper to pivot said frame to accommodate said hopper to be supported by said load bearing unit.

14. A road paver in accordance with claim 12, wherein the traction devices are rubber tired wheels.

15. A road paver in accordance with claim l2, wherein the traction devices are continuous traction tread devices.

References Cited in the file of this patent UNITED STATES PATENTS 2,351,592 Barber June 20, 1944 

